Barack Obama, America's Fundraiser-in-Chief, visited San Francisco today in search of still more campaign cash. Because San Francisco, home to Nancy Pelosi, has a reputation as America's most liberal city, one might think that The One would be safe from criticism here.  It is not so.   As he arrived for lunch at the Julia Morgan Ballroom in the historic Merchants Exchange Building on California Street, the San Francisco Tea Party was there to greet him,